Synaptic Loss at 39

Cognitive Impairment at 78

Memory impairment in homozygous mice at 18 months as measured by the Y maze test. APPNL/NL mice (with Swedish mutation only) were unimpaired at this age. No significant deficit was seen in the Morris water maze at 18 months.

Absent

Tangles at

Absent; although elevated levels of phosphorylated tau are observed in dystrophic neurites around plaques.